i think the name of the frame part that is hitting your new chainring is called the chainstay. if you look at a number of bikes, especially mountain bikes designed for wider tires, you'll see that some of the driveside chainstays have an intentional dent in them to provide relief for the large or even the small chainring.

you've exceeded the design limitations for the frame with your large chainring/crank combo.

fixes include, but are not limited to: wider BB spindle, different driveside crank arm with shallower dish, smaller chainring (not an option, suppose), spacing the BB out to the driveside. pretty much what has already been suggested.

i suspect the bike is a MTB and the crank is a road crank. i had the same problem when i attempted the same thing a couple of years ago. i hope it didn't take 2-3 hours of screwing around with it to determine the problem, like it did me. i eventually put the old crank back on and called it a day.